Some display devices that are utilized as monitors of various electronic devices have a function that automatically adjusts the brightness of the display surface. Such a display device detects the brightness of the display surface with a brightness sensor, and a controller automatically controls, based on the detected brightness, a drive circuit of the display surface so as to put the brightness of the display surface in a preset range.
In the display device, a display panel that includes a liquid crystal display panel or the like and a drive circuit that drives the display panel are housed in a housing of the display device. An opening that exposes the display surface of the display panel is formed in the housing, and a frame that blocks the gap between the outer periphery of the display panel and the housing is provided at the opening.
For example, Patent Document 1 discloses a display device in which a brightness sensor is installed on a frame that is positioned at the outer periphery of the display surface. Thereby, the brightness sensor detects the brightness of a specified position where a display pattern for brightness detection is displayed on the display surface.